1. Field of the Invention
The present invention relates to an inkjet recording apparatus.
2. Description of the Related Art
A line-type inkjet recording apparatus includes a line-type recording head in which a nozzle row is formed over the entire recording area. In the nozzle row, volatile components in ink contained in nozzles that are not frequently used evaporate and viscosity of the ink increases accordingly. When the viscosity of the ink increases, there is a risk that ink ejection failure will occur in the nozzles.
To prevent this, a system has been proposed in which humidified gas (air) is supplied to an area around the nozzles of the recording head to suppress evaporation of the volatile components in the ink. For example, Japanese Patent Laid-Open No. 2006-44021 discusses a recording apparatus including a humidifying unit that supplies the humidified gas to a gap between the recording head and a sheet.
A large amount of energy is used to generate the humidified gas. A large amount of energy loss occurs if the humidified gas supplied to the area around the nozzles is directly discharged to the outside of the apparatus. Therefore, according to an embodiment illustrated in FIG. 9 of Japanese Patent Laid-Open No. 2006-44021, a circulation system is provided in which the humidified gas that has passed by the nozzles is guided to the humidifying unit again by a duct and is reused.
However, this is a local circulation system that involves only the humidifying unit. Therefore, the energy efficiency of the entire system of the recording apparatus can be further increased.